C.4. Device Names in Linux

Linux disks and partition names may be different from other operating
systems. You need to know the names that Linux uses when you create
and mount partitions. Here's the basic naming scheme:

The first floppy drive is named /dev/fd0.

The second floppy drive is named /dev/fd1.

The first SCSI disk (SCSI ID address-wise) is named
/dev/sda.

The second SCSI disk (address-wise) is named
/dev/sdb, and so on.

The first SCSI CD-ROM is named /dev/scd0, also
known as /dev/sr0.

The master disk on IDE primary controller is named
/dev/hda.

The slave disk on IDE primary controller is named
/dev/hdb.

The master and slave disks of the secondary controller can be called
/dev/hdc and /dev/hdd,
respectively. Newer IDE controllers can actually have two channels,
effectively acting like two controllers.

The partitions on each disk are represented by appending a decimal
number to the disk name: sda1 and
sda2 represent the first and
second partitions of the first SCSI disk drive in your system.

Here is a real-life example. Let's assume you have a system with 2
SCSI disks, one at SCSI address 2 and the other at SCSI address 4.
The first disk (at address 2) is then named sda,
and the second sdb. If the
sda drive has 3 partitions on it, these will be
named sda1, sda2, and
sda3. The same applies to the
sdb disk and its partitions.

Note that if you have two SCSI host bus adapters (i.e., controllers),
the order of the drives can get confusing. The best solution in this
case is to watch the boot messages, assuming you know the drive models
and/or capacities.